Ocutter, Just thought I'd let you know what I have been using for several years. I have two systems, one for lawn and one for ornamentals. The lawn tank is 200 gals. using a Udor pump and a 5hp Honda. At 2gal per 1000 you can treat 100K per day. That may not be enough for some, but is more than enough for me. My ornamental system is a 100 gal with a Hypro pump and 5 hp Honda. And it has done a good job also. Both systems have done equally well, however, I find that the Hypro is the pump that everyone uses around here, so if you need parts, or someone to work on it, that seems the one to buy.